Monday, August 24, 2009

Records fall as temperatures rise nationwide

THE north is sweltering and, in historical terms, the south is rarely cold. The result, according to the Bureau of Meteorology, has been a winter of record-breaking warmth across the continent.

Temperatures in Queensland, northern NSW and the Northern Territory pushed up to 15 degrees above average over the past week. Brisbane yesterday reached 35.4 degrees, nearly 3 degrees warmer than the previous August high.

Swing down the eastern seaboard, and Victoria - notwithstanding yesterday's traditional four seasons in 24 hours - is also in the grip of a (relative) heatwave. If the next week holds its ground, it will be the hottest winter experienced since meteorologists started sending weather balloons skyward.

David Jones, the bureau's head of climate analysis, said temperature benchmarks for August had been broken in every state and territory. ''In duration, extent and the magnitude of anomalies it is beyond historical experience and it hasn't finished,'' he said.

No weather event can be attributed to climate change alone, but Dr Jones said he believed it was impossible to divorce the current variability from a long-term warming.

''We've always had heatwaves, we've always had warm spells in winter, but what we're seeing now is this combination of the warming trend and the extremes coming together to see very large and very long-lived records broken and often by substantial margins.''

As of yesterday afternoon, Victoria's average temperature across winter, factoring in the day-time maximum and night-time minimum, was 9.59 degrees - just ahead of the record set in 2005. The long-term average is 8.6.

In Melbourne, the average maximum temperature in August is 16.9, two degrees above the long-term average.

Dr Jones said it was a similar story across much of the country. ''It is still a developing situation, but in all likelihood Australia will have the warmest or second warmest winter on record,'' he said.

At Melbourne's Royal Botanic Gardens, staff have noticed plants reacting to the unseasonal heat. Gardens director Richard Barley said the golden chalice vine, Solandra maxima, usually started flowering in mid-spring. It was in full bloom yesterday afternoon.

Some records have been broken repeatedly over the past few days. In Alice Springs and the western Queensland town of Birdsville, for instance, the previous maximum temperature was surpassed on Friday, Saturday and Sunday.

Nothing in nature is uniform, of course. In NSW, the heat of the north yesterday contrasted with improving snow at the ski resorts in the south. And by yesterday afternoon, parts of Victoria were being buffeted by rain and gale-force winds.

Bureau duty forecaster Geoff Feren said wintry conditions were expected to continue today, with likely gusts of up to 110 km/h, thunderstorms, hail and snow at low altitudes. The temperature is expected to peak at 14 in Melbourne before an afternoon cool change.